From Electron Cloud
Jump to: navigation, search
 
Line 1: Line 1:
[http://www.tripath.com TriPath] has come up with a new kind of switching amplifier which they call "class T".  It operates a bit like a class D amplifier, and has similar efficiency, but much better accuracy and a very low THD.  They make [http://www.tripath.com/audio.htm several chips] at different power levels, but the [http://www.tripath.com/pb2024B.htm TA2024B] was chosen for [http://www.amazon.com/gp/product/B00009W44B/103-1555072-2363021 this Sonic Impact] model, which looks like a chintzy toy, and has a price to match, but has been getting rave reviews from audiophiles all over the net.  So I imagine this is a temporary situation; the next amp to use that chip will be in a heavy metal case and cost much more, and these cheap ones will be discontinued.
+
[http://www.tripath.com TriPath] has come up with a new kind of switching amplifier which they call "class T".  It operates a bit like a class D amplifier, and has similar efficiency, but much better accuracy and a very low THD.  They make [http://www.tripath.com/audio.htm several chips] at different power levels, but the [http://www.tripath.com/pb2024B.htm TA2024B] was chosen for [http://www.amazon.com/gp/product/B00009W44B/103-1555072-2363021 this Sonic Impact] model.  It looks like a chintzy toy, and has a price to match, but has been getting rave reviews from audiophiles all over the net.  So I imagine this is a temporary situation; the next amp to use that chip will be in a heavy metal case and cost much more, and these cheap ones will be discontinued.
  
 
So I thought it would be a good choice for the Messina corner speakers that I had installed in the bedroom several years ago; I don't need a lot of power in there, and the speakers can't handle a lot either, but I do have 4 of them, so I needed two stereo amplifiers.  I also wanted to either have the SqueezeBox control the amplifiers, or just leave them on all the time, so that I can use the SqueezeBox as an alarm clock.  Well these amplifiers are so efficient that it's not a problem to leave them on all the time.  I attemped to measure the power consumed by one of them using an [http://www.astroflight.com/e/env/0001MYnyluE8lAMnw0037Q0/store/store-Chargers.html?link=/store/store-type-tem.html&item=products:af-101n Astroflight Whattmeter] and it's less than 1 watt quiescent, and about 5 watts with music blasting pretty loud.  (It's supposed to be capable of 15 watts max, but the THD increases at higher power levels.)
 
So I thought it would be a good choice for the Messina corner speakers that I had installed in the bedroom several years ago; I don't need a lot of power in there, and the speakers can't handle a lot either, but I do have 4 of them, so I needed two stereo amplifiers.  I also wanted to either have the SqueezeBox control the amplifiers, or just leave them on all the time, so that I can use the SqueezeBox as an alarm clock.  Well these amplifiers are so efficient that it's not a problem to leave them on all the time.  I attemped to measure the power consumed by one of them using an [http://www.astroflight.com/e/env/0001MYnyluE8lAMnw0037Q0/store/store-Chargers.html?link=/store/store-type-tem.html&item=products:af-101n Astroflight Whattmeter] and it's less than 1 watt quiescent, and about 5 watts with music blasting pretty loud.  (It's supposed to be capable of 15 watts max, but the THD increases at higher power levels.)

Revision as of 21:49, 22 December 2005

TriPath has come up with a new kind of switching amplifier which they call "class T". It operates a bit like a class D amplifier, and has similar efficiency, but much better accuracy and a very low THD. They make several chips at different power levels, but the TA2024B was chosen for this Sonic Impact model. It looks like a chintzy toy, and has a price to match, but has been getting rave reviews from audiophiles all over the net. So I imagine this is a temporary situation; the next amp to use that chip will be in a heavy metal case and cost much more, and these cheap ones will be discontinued.

So I thought it would be a good choice for the Messina corner speakers that I had installed in the bedroom several years ago; I don't need a lot of power in there, and the speakers can't handle a lot either, but I do have 4 of them, so I needed two stereo amplifiers. I also wanted to either have the SqueezeBox control the amplifiers, or just leave them on all the time, so that I can use the SqueezeBox as an alarm clock. Well these amplifiers are so efficient that it's not a problem to leave them on all the time. I attemped to measure the power consumed by one of them using an Astroflight Whattmeter and it's less than 1 watt quiescent, and about 5 watts with music blasting pretty loud. (It's supposed to be capable of 15 watts max, but the THD increases at higher power levels.)

But I had to get rid of those chintzy cases which don't look good, are not suitable for mounting, and waste a lot of space (the majority of which is a battery compartment for 8 AA cells). I found in my junk-pile an extra relay box (the relay that came in it is running my pool pump, but it's in a bigger box in the garage with some other relays now) and decided it was about the right size to contain two T-amps plus a power supply. And my cable modem had been acting up, and I replaced it, so the power supply for the old one was handy, rated 12VDC nominal at 1 amp. However, after adding some stiffening capacitors, it was putting out 15.3 volts at the low quiescent power consumption of the T-amps, so I put some diodes in series to reduce it to about 14.15 volts. The chip is rated for an absolute maximum of 16 volts (higher voltages will damage it) so 15.3 was a bit too close for comfort.

Here are some pics of the results. I mounted it on a rafter in the room (a converted patio) which is next to the bedroom, and ran all the wires to it. A light switch in the bedroom (which used to be for a patio light) controls power to an outlet now, and the amplifier is plugged into that; so I can turn it off if it's not going to be used for a while, or I just want to avoid having an alarm on mornings when I don't need one. There is a wall plate in the bedroom which has an ethernet jack and two RCA plugs for inputs to the amplifiers. So it's one of the neatest installations I've ever done. Out of sight and just works.  :-) It's not an audiophile system (mostly because the speakers aren't that great) but sounds a heck of a lot better than a clock radio, and finally I get to choose the playlist for my wake-up music.